This error will stop you from connecting to RDP:

image

This is a client based issue with logging onto the server and the following registry key:

HKEY_LOCAL_MACHINESOFTWAREMicrosoftMSLicensing

Once you have deleted this try the RDP connection again, if it continues to fail then you may need to run the RDP connection as administrator for the first time.

Cheers

Paul